TWiV reviews a leaked CDC document on virulence and spread of the delta variant, and how anti-alphavirus antibodies that do not neutralize infection can nevertheless protect mice from disease.

In this week’s coverage of the coronavirus epidemic, the TWiV team discusses the fatality rate, China’s initial reaction to the outbreak, conspiracy theories, how long the virus remains infectious on surfaces, and evidence for virus in the intestinal tract.

Vincent and Rich discuss fruit fly viruses, one year without polio in Nigeria, and a permissive Marek’s disease viral vaccine that allows transmission of virulent viruses.

Vincent, Rich, Alan and Kathy review aerosol transmission studies of influenza H1N1 x H5N1 reassortants, H7N9 infections in China, and the MERS coronavirus.